Synchronizing clock



Sept. 6, 1932 J. w. BRYCE A SYNCHRQNIZING cwcx Filed April 20, 1925 GE 52 Q Patented Sept. 6, 1932 UNITED STATES PATENT JAMES W. BRYCE, OF BLOOMFIEL D, NEW JERSEY, ASSIGNOR T0 INTERNATIONAL TIME RECORDING COMPANY OF NEW YORK, OF ENDICOTT, NEW YORK, A CORPORATION or NEW YORK and to the accomplishment of maintaining all of the clocks in the system in synchronism with the master clock.-

The present invention is directed to actuation and synchronization of secondary clocks under the control of a master clock by the agency of electrical energy, and has for its object to utilize for these purposes electrical energy derived from different sources of alternating current having independent characteristics.

Another object resides in producing an electrically operated synchronizing system involving the employment of a minimum number of wires to control the secondary clocks.

Further and other objects of the present invention will be pointed out hereinafter in the accompanying specification and claims and shown in the drawing which by way of illustration show one and a preferred embodiment of my invention.

In the drawing:

Fig. 1 is a view showing the pertinent parts and wiring of a master clock in cooperative relation to the wiring diagram of a complete system.

Fig. 2 is a view of the minute arbor driving means of the secondary clocks used in the system. a

Master clock revolution per hour. The usual verge mecha nism 11' is provided. Fixed to the minute shaft are a pair of cams 12, 13, which cams are shaped and positioned to control a pair I of contacts 14. Preferably the arrangement of parts is such that the contacts 14 are closed for the synchronizing period and opened at other times. It will be obvious, however, that by a proper rearrangement of the associated parts of the system these cam contacts could sxncnaomzmd cLocx 3 Application filed April 20, 1925. Serial -No. 24,322.

operate in a reverse manner opening in the synchronizing period and closlng at other times. i

In the present and preferred embodiment I provide for a synchronizing period commencing just after the minute hand of the master clock is forty-four minutes after ,the hour and terminating just prior to the sixtieth minute, for reasons which will hereinafter appear.

Also fixed to the minute arbor 10 is a cam 15 which is adapted to control the opening and closing of a contact 16. In the preferred embodiment contact 16 is arranged to close just after the fifty-ninth minute position and open at approximately fifty-nine and a half.

For a proper functioning of the apparatus the contacts 16 should open just before com tacts 54 open at the end of the synchronizing er1o x P In addition, the master clock is provided with the usual minute impulse contacts 17 which are controlled in the usual way from a minute cam 18 or otherwise as is the custom in clocks of this sort.

For advancing or stepping forward the secondaries I provide quick acting contacts 19v and preferably operate these contacts byv attaching one of them to the verge mechanism 11. These contacts 19 will close at every swing of the pendulum if a pendulum movement is employed. i

The contacts may be mounted on the master clock according to well known means, as for example, similarly to those disclosed in m application Serial No; 722,439, filed June 26, 1924, now Patent No. 1,687,491 patented Oct. 16, 1928. r a

\ Secondary clock The secondary clock shown in Fig. 2 is of conventional form and it includes a minute arbor shaft 20 which makes one revolution per hour. This shaft is preferably advanced by means of an impulse magnet 21 which acts through the usual ratchet wheel 22 to advance the minute arbor 20 step by step each time the magnet 21 receives an impulse from the master clock. Carried by the minute arbor 20 on each secondary'clock I pro- 'utes after the hour or slghtly thereafter convide a synchronizing cam 23. Cooperating with this cam is a contact device of any desired form here shown as including a blade 24 adapted to close contacts 25 when the raised portion of the cam is under the blade 24 and to close contacts 26'when the blade 24 is on the low portions of the cam. The cam 23 is so timed that when the minute hand of the clock is opposite the fifty-ninth minute the blade 24 has just fallen off the high point 27 of the cam 23 breaking contact 25 and making contact 26. The cam rise 28 in the present embodiment of the invention is disposed substantially 180 around the cam from the drop-elf point 27 so that at twenty-nine mintacts 25 are closed and contacts 26 will be opened. The parts are so arranged that at no time except momentarily during the shifting of blade 24 are both contacts25 and 26 open.

Referring to the circuit diagram, alternating current is supplied to the secondary clocks from two sources of power, not shown, depending upon the position of double switch 29. When this switch is in its lowest position current will be taken from bus-lines 30, 31, and when in its upper position, current of a different frequency will be taken from bus-lines 30, 31'.

The systems will be designed to be used with the two frequencies of current that are in common use for lighting and power purposes in any particular community, but for convenience in describing my invention I have chosen to refer to the 30--31 bus-lines as carrying a current having a frequency of 30 but for simplicity in the present description a.

ground return is utilized from the secondary clocks.

N ormal operation The first operation to be described will be the normal minute impulse operation for controlling the secondary clocks. For clarity it will be assumed that all of the clocks at this moment are at a position somewhere between the hour reading and forty-four minutes later.

The circuits of the master clock always remain across the thirty cycle bus-lines 30-31, and current is taken therefrom over wires 32, 33 and 34, through minute contact 17, wire 35, master relay coil 36, wire 37, and back to line 31. This energizes the master relay coil 36 once per minute attracting relay armature 38 and causing the current to flow from the thirty cycle line through switch 29, line A, armature 38, feed line 39, either contact 25 v or contact 26, arm 24 and to the clock impulse Synchronization The synchronizing period starts just after the forty-fourth minute when contacts 14 are timed to close. This causes current to flow from bus-line 30, through wires 32, 33, 42

and contacts 14 now closed, synchronizing relay coil 44 and back to bus-line 31. The energization of synchronizing relay coil 44 attracts the armature of switch 29 thereby throwing the secondary clock circuit over to the sixty cycle bus-lines 30', 31'. This position of switch 29 is maintained until just prior to the sixtieth minute by reason of the continued energization of coil 44. During this period the secondary clocks which are on time or slow are advanced step by step on each minute by the minute impulses of magnet coil 21 caused by the impulse of cur-- rent from the sixty cycle bus-lines 30, 31 through line A, armature 38, line 39, condenser 40, contact 25, magnet coil 21, and ound C. The secondary clocks that were ast will have stopped at the hour position, for reasons which will appear hereinafter.

The condenser is designed to have a capacity reactance so related to the inductive reactance of coil 21 that when a thirty cycle circuit is flowin through the coil circuit, the average strength of the current will be substantially the same whether the condenser be in series with the coil or whether only the coil is in the circuit.

When this condenser and coil are in series they must create opposition to the flow of a current of sixty cycles to such an extent as to permit an average current strength substantially equal to the average current strength existing when a thirty cycle current is flowing. From the foregoin it is apparent I that when the condenser is ta en out of the series circuit, a sixty cycle current source will not be suflicient to impress a current strong enough to energize ma et coil 21 because the opposition to the ow of a current of sixty cycles caused by the reactance of the magnet coil is too great. It will be understood that the opposition to flow of current in each branch or circuit including impulse magnet 21 is dependent upon whether or not the same current that flows through the electromagnet also flows through the device 40 in that branch or circuit. The effect of the device 40 is to change the opposition of the branch or circuit with which it is associated to the flow of current in accordance with whether the device is or is not in effective mociation with the circuit.

Hence, between the sixtieth and fortyfourth minute as indicated by the master clock when the thirty cycle bus-lines are connected with the secondary clocks, current will flow through the secondary clocks of sufficient strength to energize magnet coil 21 on each minute impulse, whichever one of contacts25 and 26 is closed. However, during the synchronizing period starting just after the forty-fourth minute only the secondary clocks having contacts 25 closed will be actuated by the minute and acceleration impulses hereinafter described. Those having contacts 26 closed will stop because the current will not be of sufficient strength to actuate the ,coil magnets 21.

In the diagram three secondary clocks are shown marked respectively X, Y, and Z. Clock X is assumed to, be on time with its minute hand in agreementwith the master clock. Clock Y is assumed to be fifteen minutes fast and clock Z fifteen minutes slow. Synchronizing cam 23 of clock X is about the center of its high portion thus closing contacts 25. Cam 23 of the Y or fast clock has reached such position that blade 21 has dropped off step 27 closing contacts 26 and opening contacts 25. Cam 23 of the Z or slow clock has just passed the rise and reclosed contacts 25 opening contacts 26.

For the reasons previously explained, during the period of synchronization, impulses of sufficient strength to energize magnet coil 21 can be delivered to a secondary 'clock only when condenser 40 is in its circuit and this only occurs when contact 25 is closed. Clock Y will therefore remain stationary until the end of the synchronizing period. Clocks X and Z, on the other hand, are in such position that contacts 25 are closed and they therefore are in condition to receive minute impulses during the synchronizing period. The clocks X and Z then step along in the usual way, re-

- ceiving the normal impulses every minute untilthe end of thesynchronizing period is reached.

Just after the fifty-ninth minute, as shown by the master clock, the cam 15 reaches a position to close the contacts 16. Current now flows from the source 30 over wire 32, wire 46, contacts 16, wire 47, contacts 19 to wire and master relay coil 36, wire 37, and back to bus-line 31. The contacts 19 close in comparatively rapid succession, for example,

once every two seconds and energize coil 36 a plurality of times which attracts armature 38 a plurality of times thereby sending a succession of fast or acceleration impulses over wire A. It will be understood that on clock X which is on time contacts 25 will have opened just after the fifty-ninth impulse and before contacts 16 were closed, thereby preventing the fast step-up impulses from effecting it. Clock Z, on the other hand, will have the parts in such position that contacts 25 are closed so that the fast impulses are received by it which causes the clock to he stepped forward or accelerated turning around the synchronizing cam until it reaches a position to open contacts 25. All of the clocksX, Y and.Z are now in syn chronism with the master clock. After contacts 19 have sent the selected number of fast impulses, contacts 16 will open thus rendering contacts 19 ineffective to send further impulses. Shortly after contacts 16 open and just before the sixtieth minute impulse, contacts 14 will open thus de-energizing the synchronizing relay coil 44:, releasing the armature of switch 29 and allowing the switch to throw the secondary clock circuit across the thirty cycle bus-lines 30, 31.

On the sixtieth minute, contacts 17 will close and thereafter send the usual minute impulses to the secondary clocks. Inasmuch as contacts 26 on all of the clocks X, Y and Z are now closed they will be all stepped along step-by-step in synchronism as the master clock controls the periodic closing of armature 38. v

This would be the usual operation of a system, but if a secondary clock should be interfered with by accident or otherwise so that it would be behind time a greater number of minutes than there are acceleration impulses furnished by the master clock, it would still be late at the hour impulse and contacts 25 would not have opened. This clock would still continue to operate because the thirty cycle current which feeds the secondary clocks for the sixtieth impulse and those thereafter will produce a current of sufficient strength to energize the magnet coil 21 whether the condenser is in or out of the circuit. On the next hour this delinquent clock would be brought into synchronism with the others, as already described. However, the timing of thevarious cams in the system disclosed herein has been found satisfactory to' maintain all clocks in synchronism and it is only under unusual circumstances that any secondary clock would be so slow as not to be on time on the sixtieth minute.

It will be understood that'if in any case it is required to correct the time of the entire system, as for example, when the master clock is running fast or slow and this correction is to be within the range permitted by the synchronizing period it is only necessary to reset the hands of the master clock to the desired extent. The secondaries will then set themselves within the next hour. If the amount is in excess of the synchronizing period for which the system is designed, for example, when a daylight saving correction is required, a manualcontrol is brought into operation as shown'in Fig. 1 which will now be described. Referring to the diagram a wire 48 is provided terminating in a switch V with the switch point=or wire 48.

point as shown. 7 A switch member 49 is disposedin line 32 and for the usual running position is closed in the position shown. To retard the secondary clocks the switch 49 is displaced to the open or off position breaking line 32 and also being out of contact with the switch point on wire 48. This switch is maintained open for the desired retarding period. If it is desired to advance the clock the switch 49 is thrown to connect The effect of connecting switch 49 with wire 48 is to cause the fast set-up contacts 19 to come.

into action and rapidly advance the various secondary clocks. The switch 49 will be held closed until the secondary clocks advance to the desired extent. For example, to advance all of the clocks one hour with contacts 19 closing every two seconds it will take two minutes to bring about the proper advance of the secondaries.

It will be understood that it is not essen tial to hold switch 49 closed for the exact pe-' to open switch 49 for approximately the desired retarding period.

'While in the present embodiment I have selected a synchronizing period of fifteen minutes it will be understood that this period is given merely for purposes of illustration and that this period may be greater or less as desired. In conventional clock systems of the present day this period has been found to be ample for all practical purposes.

In the present system it will be apparent that the master clock sends out over a circuit normal impulses produced by a thirty cycle current for a definiteperiod and then automatically shuts off the thirty cycle source of current and connects a sixty cycle source of current across the same circuit for another period of time which corresponds to the synchronizing period and during which normal and fast impulses are sent out. All of the apparatus necessary to produce this operation is self-contained in the master clock.

The synchronization of the secondary clocks is dependent upon the utilization of the current characteristics sent out by the master clock and the utilization is controlled by the devices therein and its own chronologic condition. These devices selectively determine whether the secondary clocks shall receive normal impulses, fast impulses, or whether they be connected so as not to receive any impulses for a time.

-vice for actuating the same, and means controlled solely by said translating device for determining w ether the electrical energy from said common circuit will be utilized for advancing the secondary clock.

2. In a synchronizing system including in combination, a master clock having means for controlling the distribution of electrical energy of different frequency characteristics over a common circuit, means in said clock for controlling the periodic excitation of said common circuit, a plurality of secondary clocks connected across said common circuit each having a translating device for actuating the same, and means controlled solely by said translating device to determine whether or not each secondary clock will be actuated by impulses caused by said periodic excitation of said common circuit.

3. In 'a synchronizing system, the combination of a master clock, a main circuit, means for sending out over said main circuitl a series of normal and rapid im ulses periodically, sources of current of di erent frequency characteristics, and means to determine ,of which frequency characteristic algae series of normal and slow impulses will 4. In a synchronizing system, the combination of a master clock, a main circuit, means for closing said circuit successively for a series of normal excitations and a series of rapid excitations, sources of/current of different frequency characteristics, and means controlled by the clock for determining which of said sources of current will excite said main c rcuit.

5'. In a synchronizing system, the com sources of alternating current, means controlled by the clock for connecting said main circuit with either one of said sources of current, and means controlled by said clock for repeatedly rendering said main circuit capable of excitation by the one of said sources which is connected.

. 7. In a synchronizing clock system, the

combination of a .master clock including means for controlling the distribution of electrical energy of different frequency characteristics, a main circuit, means to cause said electrical energy to be distributed by a continuous flow of impulses over said mam circuit, a secondary clock, leads connected across said-main circuit, and meansv controlled by the chronologio condition of said secondary clock for controlling the utilization of the current transmitted through said eads for operating said secondary clock.

8. In a synchronizing clock system, the combination of a master clock including means for controlling the distribution of electrical ener y of different characteristics, a secondary c ock, a circuit for conducting said electrical energy to said secondary clock, means interposed in said circuit for causing currents of different strengths when currents of difi'erent characteristics are of permitting currents of substantially equal strength to flow therethrough regardless of which of the selected frequencies is connected therewith, and a switch controlled by the secondary clock for changing the relation of said means so that the strength of the current of highest frequency is diminished.

10. In a secondary clock, the combination of a shaft, a ratchet wheel on said shaft, an electromagnet for actuating said ratchet wheel, two branch circuits oneof which contains a condenser, a switch, and means controlled by the rotative position of said shaft for connecting either one of said: branch circuits in series with the electromagnet.

11. A secondary clock having in combination electromagnetic actuating means, and means including a condenser for selectively controlling the operation or non-operation of said means.

12. In a secondary clock having an electromagnetic actuating means for the clock hands, a condenser, and means includingv switch means controlled in operation by the clock hands for bringing said condenser into or out of circuit for the purpose described.

13. In a secondary clock having clock hands and electromagnetic actuating means therefor, a condenser coordinated in capacity reactance with the inductive reactance of said means for suppressing or permitting the operation of said means, and means controlled by the position of the clock hands for controlling the efi'ectiveness of said condenser.

14. A secondary clock comprising, in combination, translating means for driving said secondary clock, electro-magnetic means for actuating said translating means, a circuit, an electro-magnet in said circuit, a plurality of leads, a condenser in one of said leads, means for connecting either one of said leads in series with said circuit, and means for controlling the position of said last named means.

15. In av synchronizing clock system, including in combination, amaster clock having means for controlling the distribution of electrical energy of different characteristics over a main circuit, asecondary clock, translating means for driving said secondary clock, electro-magnetic means for actuating said translating means, a plurality of leads, each lead including said electro-magnetic means, and a condenser in one of said leads coordinated in capacity reactance with the inductive reactance of said electro-magnetic means whereby the effect of the current flowing through said electro-magnetic means is sub- N stantially'diminished or unimpaired depending upon the character of the current flowing over said main circuit.

16. A synchronizing clock system comprising, in combination, a master clock, a source of current of one characteristic, a source of current of another characteristic, a plurality of controllin circuits, a main circuit, a relay in one of sand controlling-circuits for connecting said main circuit to either one of said sources, a relay in another of said controlling circuits for closing said main circuit, a secondary clock, translating means for driving said secondary clock, electro-magnetic means for actuating said translating means, a plurality of leads, each lead including said electro-magnetic means, a condenser in one of said leads, means for connecting either one of said leads in series with said main circuit, and means controlled by said secondary clock for positioning said last named means.

17. A'synchronizing clock system including a master clock and a secondary clock having operating means therefor with a line circuit therebetween with means at the master clock for impressing current of different frequency characteristlcs at different times upon the line circuit, and meansat the secondary clock for corelating the operating means of the secondary clock-to function or stop functioning in accordance with the frequency of the current which is being sent over the line circuit and in accordance with the chronological condition of the secondary clock.

18. A secondary clock which receives operating and controlling current of different frequencies over a single line circuit, said secondary clock having in combination therein a translating means, and means for controlling the same for operation or non-operation under the conjointcontrol of the frequency of current which is being received over the line and in accordance with the chronological condition of the clock. I

19. A synchronizing clock system including master and secondary clocks, and means for effecting synchronization therebetween, comprising in combination, means at the master clock for transmitting current impulses of different frequency, and means at the secondary clock for selecting which frequency of current is to be effective for operating the secondary clock in accordance with the relative chronological condition of the secondary clock and master clock.

20. A synhronizing clock system including a clock circuit, a master clock connected thereto and secondary clocksalso connected thereto with means for effecting synchronization between the secondary and master clocks, said means comprising in combination means for transmitting clock controlling currents of different frequencies by said master clock, and means at said secondary clocks controlled by the relative chronological conditions of a given secondary clock with respect to the master clock for selecting which frequency of current is to be effective or non-effective for operating the secondary clock and for thereby advancing or stopping the secondary clock.

21. A secondary clock which receives current of different frequencies over a common line at different periods of time, and means in said secondary clock for selectively determining which fr uency of current is to be effective or non-e ective for operating said clock, said means includinga translating device and selecting devices for calling the same into and out of operation under the conjoint control of the frequency upon the common line and the chronological condition of the clock.

22. A secondary clock for use in synchronized clock systems and comprising a common impulse magnet which by its own action I effects all advancing movements of the clock which are required for normal step-by-step advance or for accelerating the clock if the same is slow, with means at each secondary clock for suspending its advance under certain chronological conditions of the clock and permitting a reinitiated advance of the clock under the action of the impulse magnet after its action has been suspended, said means including switching means in the secondary clock for altering the circuit rela tions of the impulse magnet, and means including a single line circuit extending into the clock from the master clock for sending thereinto from the master clock both the normal and fast impulses which normally advance and accelerate the clock and for also transmitting thereto current of special characteristics which upon its reception by the clock is adapted to reinitiate an advance thereof after its operation has been suspended. L i

23. A synchronized clock system including a master clock and a secondary clock of the impulse type, and a single line circuit connecting the same for operating and synchronizing the clocks and having in combination a common impulse magnet which is employed in the secondary clock for both advancing the clock for normal step-by-step operations and for accelerating it by step-by-step operations when it is slow, and supplemental devices in the secondary clock which are responsive to current of special character which is sent over and received by the secondary clock from the common line circuit from the master clock for efiecting an increase of How of current through the impulse magnet after it has performed its accelerating operations to synchronize the secondary clock with re spect to the master clock. 24. A secondary clock which comprises in combination, time indicating means and step by step mechanism for operating the same, an electromagnet which operates and causes the step by step mechanism to advance the indicating means at a normal rate when the time indication is correct and at a rapid rate when the time indication is slow, an electrical device in the secondary clock adapted at times to be concurrently energized with the impulse magnet, means operated by the step by step mechanism when the time indicatin means has reached a predetermined position for altering the relation of said device'to the cooperating impulse magnet so that the operation of the step by step mechanism is suspended until current of a characteristic different from that of the current which caused the time indicating means to bebrought up to said predetermined position is supplied whereu on advance 0 the time indicating means y the 'electromagnet is resumed.

25. In combination, a time indicating means and step by step mechanism for operating the same, an electromagnet which operates and causes the step by step mechanism to advance the indicating means at a normal rate when the time indication is correct and at a rapid rate when the time indication is slow, a circuit including said electromagnet, means called into operation when the time indicating means has reached a predeter- -mined position for changing the opposition of said circuit to the flow of 'current therethrough thereby suspending the operation of the time indicating means until current of a'difierent characteristic is supplied to said circuit, said means being controlled by the time indicating mechanism for subsequently again changing the opposition of said circuit to the flow of current therethrough.

26. A secondary clock of the impulse type in which a single circuitleads into and out of the clock over which all advancing im pulses are sent to the clock, a single magnet in the clock for receiving the advancing impulses and for effecting all advancing movements of the clock, and means including a selectin device in the secondary clock controlled by the chronological conditionof the .clock for varying the amount of energization of the single magnet and for determining the operativeness or non-operativeness of the impulse magnet to advance the clock by current impulses of one character or another which flow into the clock-over the single line "circuit.

27. A synchronized clock system of the impulse type including a master clock, one or more secondary clocks and a single line cir- 'cuit extending from the master clock to the secondary clock or clocks, means atthe master clock for sending all advancing impulses over said single circuit and for sending certain advancing impulses with a characteristic which differs from that of other advancing impulses, and including in combination in each secondary clock a single magnet which receives the advancing impulses and effects all advancing movement of its clock, and means including a selecting device in each secondary clock which includes cooperating parts and which parts are all positioned and controlled as to their selecting position relatively to each other for selecting action solely b the forward movement of the secondary c ock, for determinin the operativeness or non-operativeness o the impulse magnet to advance the clock when supplied with current impulses of one character or another which flow into the clock over the single line circuit. I

28. A secondar clock comprising in combination, time in icating means, a single impulse magnet with a single armature for effecting all movement of the time indicating.

means, and means having cooperating relatively displaceabl e parts for suspendingnormal advance of the clock when fast under continued reception by said magnet of current impulses, all of said displaceable parts being controlled as to their relative effective position for suspending action wholly b said single armature and in accordance wit the chronological condition of the clock.

29. A secondary clock system including a master clock, one or more secondary clocks and a single line circuit connecting the same with means at the master clock for sending out over the single line circuit current impulses of one characteristic at certain times and at other times at least one current impulse of another and different characteristic and including in combinationin the secondary clock or clocks a single impulse magnet in each clock which is adapted to advance the clock by step by step operations both for normal advance and also for accelerating step by step advance, and means at the secondary clock for correlating the single impulse magnet to' functionor stop functioning.

in accordance with the characteristic of the current impulses which are being sent over the single circuit from the master clock and in accordance with the chronological condition of the secondary clock, said correlating means controlling the action of the impulse magnet by altering the electrical characteristics of the circuit in the secondary clock which includes the magnet.

30. The method of both actuating and synchronizing one or more secondary clocks by p the use of current impulses which are of distinctive character, which comprises the sending from a masterclock over a main line first current impulses of a special characteristic and then current impulses of another special k of said periods to be ineffectual upon a secondary clock when the secondary clock is fast by varying the connection of the clock to the line or causing the secondary clock to continue to be affected by said current impulses duringthe same period when the secondary clock is slow by maintaining unchanged the connection of the clock to the lines 31. The method of actuating and synchronizing one or more secondary clocks from and by and in cooperation with a master clock which comprises sending out from the master clock under its control first a series of impulses of one controlling special characteristic and thereafter sending out from the master clock during a recurring and subsequent period impulses of another special characteristic including a number of impulses which are sent out at a faster than normal rate and operating a secondary clock by either of saidcharacter of impulses and also rendering certain of said impulses received by the clock ineffective tocontinue the operation of the clock when it is fast by altering the connection of the clock to the line.

32. A method of actuating and regulating one or more secondary clocks by the use of current impulses of different special characteristics which are sent out from a master clock comprising initiating successive current impulses including impulses at a normal rate and at afaster than normal rate over a main circuit, controlling the special characteristics of said impulses during successive periods of definite duration so that the current impulses will be of one special characteristic over/the main circuit during one period of time of operation of the master clock and of different special characteristic over the main circuit during another period of time of operation of the master clock operating a secondary clock step by step by said current impulses, during one of the periods rendering certain of said current impulses ineffective to operate a secondary clock if it be 'fast by changing the quantity of current flowing into such fast clock or continuing to operate a secondary clock if it be on time or slow and proceeding with the continued operation of the secondary clock at the beginning of the next succeeding period of time.

33. The method of actuating and synchronizing one or more secondary clocks from a master clock over a common single line main circuit which comprises initiating and sending out over the same main line circuit current impulses at a normal rate and at a faster than normal rate and in sending impulses of one special characteristic for a certain period of time as determined by the master clock, then emitting by the master-clock and sending out over the same main line circuit at least one current impulse of a difi'erent special characteristic for another succeeding period of time as determined by the master clock, and in effectively actuating the secondary clocks ,by impulses of either special characteristic under certain chronological conditions of the secondary .clocks, and in rendering received impulses of certain special characteristics themselves ineffective to actuate the secondary clocks under certain chronological conditions of such clocks by altering the opposition of circuits in the clocks to the flow of current therethrough and in thereafter upon receipt of at least one impulse of a different special characteristic but of the same duration by the secondary clocks causing the same to again become effective to recontinue their ste by step advance under such impulses of di ferent characteristics. a

34. A method of actuating and synchronizing secondary clocks over a common line circuit from and by a master clock which comprises emitting bythe master clock current impulses of one special characteristic for a certain period of time of definite duration and thereafter emitting impulses of a different special characteristic from the master clock for another period of time of definite duration and then repeating the operation and in send .ing out said impulses. sending some at a normal rate and others ata faster than normal rate, and in effectively operating secondary clocks step by step by actuating impulses of either characteristicunder certain chronological conditions of the secondary clocks and under other chronological conditions .of the the step by step advance of the secondaries in I synchronization with the master clock.

, 35. The method of actuating and synchronizing secondary clocks over a single line circuit from a master clock wherein normal impulses and faster than normal impulses are emitted from the master clock over the singleline circuit to the secondary clocks "which comprises varying by the master clock the characteristics of the emitted impulses which are sent over the single line circuit so that certain impulses have a common special characteristic and so that at least one of the emitted impulses has a different special characteristic from that of the other impulses which have the common characteristic and also by the master clock coordinating the characteristics of the emitted impulses themselves to and in accordance with the chronological condition of such master clock, and also coordinating the secondary clocks for effective operation, ineffective operation, or resumed operation after an ineffective period by varying the current flow conditions within the secondary clock itself, in conjoint accordance with the characteristics of the impulses which are'received in the secondary clocks and in accordance with the chronological-condition of the secondaryclocks.

36. The method of operating a secondary clock from a master clock which comprises transmitting current through a circuit from the master clock to the secondary clock, suspending operation of the secondary clock by thesaid currentby changin at the secondary clock the opposition to the ow ofthe current in the circuit, and resuming operation of the secondary clock by supplying to the circuit from the master clock current of a different characteristic? 37. A secondary clock for use in synchronized clock systems and comprising a common impulse magnet which by its own action upon reception of one characteristic or another and difierent'characteristic efiects all advancing movements of the clock which are required for normal step by step advance or for accelerating the clock if the same is slow, with means at each secondary clock for suspending its advance. under certain chronological conditions of the clock and permitting a reinitiated advance of the clock after its action has been thus suspended, said means including means for changing the amount of 38; A synchronized clock system including a master clock and a secondary clock of the impulse type, and a single line circuit connecting the same for operating and synchronizing clocks and having in combination a common impulse magnet which is employed in the secondary clock for both advancing the clock. for a normal step by step operation and for accelerating it for step by step operations when it is slow, and supplemental devices in the circuit of the impulse magnet inthe secondary clock which are controlled. by the chronological condition of the @secondary clock itself and also correlated for control of eflective or ineffective supply of current to the common impulse magnet in. accordance with the supply of current of one special char-- 'acteristic or another which is sent by the master clock to the secondary clock over a common line circuit which transmits the nor mal and fast impulses whereby the clock advance may be suspended, resumed, accelerated or continued as required. 39. An electrical synchronizing clock system of the impulse type comprising in combination amaster' clock for transmitting ormal and fast impulses, a secondary clock of the impulse type, a single line circuit con- 'necting said clocks and through which normaladvance and synchronization of the sec-Q ondary clock by the master clock is effected, a

single impulse magnet in said secondary.

clock for effecting all of its advancing movements under the control of said master clock through said single line circuit, means controlle the chronological condition of the secon ar clock itself and adapted by the operation 0 the secondary clock only and a wholly: independently of control from the A master clock to alter the responsiveness of.

the clock to impulses received over the single line circuit from-the master clock, said last mentioned means in the secondary including means which is effective when its responsiveness is so altered to render the clock receptive and operative upon receipt of anfimpulse of a different characteristic from the master clock. r

In testimony whereof I'hereto afiix my signature. i

' JAMES W. BRYCE. 

